jacobs



June 26, 1923. 1,459,769

' O. B. JACOBS REPEATER CIRCUITS Filed May 17, 1919 2 Sheets-Sheet 1 IN V EN TOR.

A TTORNEY June 26, 1923. 1,459,769

0. B. JACOBS REPEATER CIRCUITS Filed May 17, 1919 2 Sheets-Sheet 2 IN VEN TOR.

0. Jambs BY W A TTORNEY sition.

Patented June 26, 1923.

UNITED STATES 1,459,769 PATIENT OFFICE.

OLIVER B. JACOBS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR 'I'O AMERICAN TELE- PHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

REPEATER CIRCUITS.

Application filed May 17,

To all a; ham it may concern:

:Be it known that I, OLIVER B. JACOBS, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain Improvements in Repeater Circuits, of which the following is a specification.

This invention relates to-transmission circuits and more particularly to transmission circuits in which repeaters are employed.

One of the objects of this invention is to simplify the apparatus and reduce the (3X pense connected with the installation of repeater equipment for telephone lines. Another object of the invention has reference to the provision of means whereby one repeater may be employed for a plurality of connecting circuits. Other and further objects of the invention will more fully appear in connection with the detailed description hereinafter given.

, lVhere cord circuit repeaters are employed in the establishment of connections between long distance transmission lines, it is customary to provide a repeater unit for each repeater cord at each position. Under certain circumstances, however, it is desir able that the same repeater. unit be used for repeater cords at two positions so that the amount of apparatus necessary may be reduced. The repeater unit comprising the amplifiers. relays, coils, etc, is usually arrangeil at a point'somewhat distant from the switchboard and is connected with the switching cords and controlling keys such as the listening, splitting and repeater control keys by means of a series of conductors extending from the repeater ,unit to the switchboard position. In accordance with the present invention the apparatus is so arranged thatthe conductors leading from the repeater unit may be switchedinto con nection with conductors leading to either of two switchboard positions. Means are provided whereby when the operator at one position utilizes a repeater cord at that position in establishing a connection, the conductors leading from the repeater unit are switched into connection with the switching plugs and controlling keys of that cord so that'the repeater is rendered independent of the switching plugs and controlling keys of the corresponding cord at the other po- At-the same time abusy lamp is 1919. Serial No. 297,866.

derstood by reference to the following description when read in connection with the accompanying drawings, Figs. 1 and 2 of which when taken together constitute a cir cuit diagram of one embodiment of the invention.

Referring to the drawings the usual twoway two repeater circuit including vacuum tube amplifiers A and A is shown in Fig. 2. Line conductors L and artificial line conductors N are associated with the one end of the repeater and line conductors L and outgoing plug P at said position. These twin plugs are so arranged that upon being inserted in corresponding twin jacks real transmission lines are connected with the line conductors L and L respectively and artificial lines suitable for balancing the transmission lines are connected to the conductors V and N respectively. In the idle condition of the circuit the repeater is disconnected from the line conductors L and L, the conductors L being connected to cord conductors C which normally extend over cord conductors C overthe contacts of the splitting key K and over cord conductors G which are normally connected to cord conductors C normally associated with line conductors L of the repeater circuit. A listening key K is provided whereby the operators set may be bridged across the toll cord circuit formed by the conductors C, C C and O. A repeater control key K is also provided for controlling the operation of the repeater. V

The circuits associated with the plugs P and P and the keys K K and K normally extend over the contacts of a series of switching relays 1, 2, 3, 4 and 5. When these switching relays are energized, these connections are opened and the various circuits leading from the repeater unit of Fig. 2 are associated by means of alternative connections with a similar repeater cord 10- cated at a second operators position desig nated in the'drawing as Y. The cord circuit at position Y terminates in twin plugs P and P and is provided with a listening key K splitting key K and repeater control key K The transmission conductors L, N, C, L, C and N of the repeater unit of Fig.2 may be connected over alternative contacts of the switching relays 1 to 5,.

inclusive, and over alternative transmission connections L N C L N and G to the sivitching plugs and controlling keys of the cord" circuit at position Y. The various circuit controlling conductors leading from the repeaterunit to the switchboard positions may also be switched by means of the relays 1 to inclusive.

The circuitsof the switching relays are so arranged that if the operator at pus-.- tion X inserts either or both of the plugs P and P into corresponding jacks, relays 1 to 5 will be removed from the control of the operator-at position Y and the various conductors leading from the repeater unit will remain. connected-over the back contacts of the switching relays to the appara tus of the cord at position X. Busy lamgs (iand 7 are provided at positions and .7 respectively and upon the establishment of the circuit condition above referred to, busy lamp 7. at positionY is caused to glow to indicate to the operator at that position that the repeater is in use in connection with the cord. at position X. If the operator at position Y sho uld first obtain control of the circuit by inserting either or both of the plugs P P in corresponding twin jacks, the switching relays l to 5, inclusive, will be actuated to switch the connection from the repeater unit of Fig. 2 to the cord circuit apparatus at position Y thereby removing the repeater from the control of theopcratol. at position X. At the same time the busy lamp 6 at position is caused to glow to indicate to the operator at that position that the repeater is in use.

Further details of the apparatus may be best understood from a detailed description of the operation which, is as follows:

7 Assuming. that the operator at position X desires to establish a connection between an incoming transmission line and an outgoing transmission linetl'irough the repeater shown in Fig. 2. The. operator will insert the twin plug P in the twin jack of the in-- coming line thereby connecting the incoming line to conductors L and the corresponding artificial line to conductors N A circuit is now completed. from the grounded sleeve contacts of the twin jack over the sleeve contacts of the plug P through the winding ofrelay 8 over the left hand. contact of relay 10.and;left hand back contact of relay 11 to battery. Relay 8 at its right hand contact disconnects the battery which is normally connected over the right hand back; contactsof relays 8 and 9 to the windings of relays 10 and 11 so that relays 10 and 11. will not operate in case the operator at position Y should insert either or both of the plugs P and P into line jacks. At its front right hand contact relay 8 connects battery to the busy lamp 7 at posl tion Y thereby causing the lamp to glow to indicate to the operator at position Y that the repeater is engaged.

At its left hand front contact relay 8 con- UBLYS ground through the resistance 12 and through the winding of relay 13 to battery. Relay 13 upon being energized completes a circuit from ground over its lower front contact over conductors 14 and 15 over the backycontacts of ringing responsive relays 16 and 17 and over conductor 18 through the winding of slow release relay 19 to battery. Relay 19 upon being energized opens the circuit which would otherwise have. been completed for relay 20 from ground over the lower frontcontact of relay 13 over the back contact of relay 19 and through the winding of said relay 20 to battery.

A transmission circuit now extends from the incoming line over the left hand tip and ring contacts of the lug P line conductors L left hand ack contacts of switching relay 2, line conductors L, back contacts of relay 21 over conductors C, right hand back contacts of switching relay 8 over conductors C over the right hand normal contacts of splitting key K over conductors 22, left hand normal contacts of splitting key K conductors C left hand back contactsof switching relay 3, *condurw tors C, back contacts of relay 23, conductors L, back right hand contacts of switching relay at and over conductors L to the ri ht hand tip and ring contacts of the plug The operator by throwing the listening key K may bridge her setacross the transmission circuit above traoedat points 24 and 25.

In order to complete the connection the operator now inserts the plug P in the jack of the outgoing line and actuates the repeater control key K the listening key K having in the meantime been restored. The insertion of the plug P in the jack completes a circuit from the grounded sleeve contacts of the jack over the sleeve of the plug P; through the winding of relay 9 and over the back left hand contact of relays 10 and 11 to battery. Relay-9 at its rights hand contact opens the circuit of relay 10 and 11 at another point to further prevent the actuation of these relays. At its left hand front contact relay 9 connects ground through the resistance 26 and through the winding of relay 27 to battery. Relay 2? upon being energized at: its lower contact connects ground to point 28 but no circuit changes are produced as a result of winding of said relay over conductors 30- and 31 over the right. hand make contacts of key K over conductor 32, inner back contact of relay 5 and over conductors 33 and 14 to point 28 and thence in parallel over the lower front contacts of relays .13 and 27 to ground. Relay 29 upon being energized cdnnects the filaments of the amplitiers A and A in series with the-filament battery B thereby rendering the amplifiers operative.

The actuation of repeater control key K also completes a circuit from the lower grounded contacts of relays 13 and 27 to point. 28 over conductor 34, left hand contact of relay 1, conductor 35, conductor 36, lower normal leftthand and right hand contacts of splitting key K right hand normal contact of listening key K over conductor 37 inner right hand back contact of relay 1, conductor 38, upper front contacts of re lays 13 and 27, conductors 39 and 40, left hand make contact of repeater control key K conductor 41,- left hand back contact of relay 5, conductors 42 and 43 throu'ghthe Winding of relay 44, back contact of relay 45, conductor, 46 and thence in parallel through the windings of relays 21 and 23 to battery. Relay 44 upon being energized opens the short circuits which are normally closed about the primary windings of the input transformers 47 and 48 of amplifiers A and A respectively and connects said input transformers to the input bridges 49 and 50 of the repeater. Relays 21 and 23 disconnect the line conductors L and L of the repeater from the cord conductors C and C and connect said line conductors through windings of transformers 51 and 52 to the artificial line conductors N and N respectively. i 7

The two-way repeater comprising amplifiers A and A'- is now operative and is interconnected between the incoming and out-- going transmission lines through the connections to plugs P and P 9 Transmission from the incoming line passes over conductors L left hand back contacts of relay 2, conductors L, front contacts of relay 21 over input bridge 49 through theinput transformer 47 to theamplifier A which amplifies the transmitted variations and trans- Inits them from the output circuit 53 and through the transformer 52 where the energy divides, one-half being transmitted over the front contacts of relay 23 over conductors L, ,right hand contacts of relay 4 and conductors L to the outgoing line and the other half being transmitted over conductors N through the winding of relay v Relay 20 at its righthand front contact com.-

lefthand back contacts of relay 4 and conductors N, to the artificial line. In a similar manner transmission from the outgoing line comes in over conductors L over the right hand back contacts of relay 4, conductors L, front contacts of relay 23, input bridge 50 and through the transformer 48 to the amplifier A, The amplified variations are then transmitted from the output circuit 54 through the transformer 51, one-half of the energy being transmitted to the incoming line over the front contacts of relay 21 and conductors L, left hand back contacts of relay 2, and conductors-L and the other half being transmitted over conductors N, right hand back contacts of relay 2xand conductors-N to the artificial line.

If, with the circuits in the condition just described, ringing currents should be transmitted over the incoming line, said ringing current would flow over conductors L and L to the ringing responsive relay 17. Said relay upon being energized by the ringing current opens the circuit previously traced for the slow releasing relay 19 which, upon permitting its armature to retract, completes a circuit from ground over the front contacts of'relays 13 and 27 to point 28 and thence over the back contact of relay 19 and 20 to battery.

pletes a circuit from ground over the lower front contacts of relays 13 and 27 to point 28, over conductor 34, left hand back contact of relay 1, conductors 35. and 36, lower normal contacts of splitting key K right hand normal'contact of listening key K conductor 37, inner right hand back contact of relay 1, conductor 38, upper front contacts of relays '13 and 27, conductors 39 and 40, left hand make contacts of repeater controlkey K conductor 41, left hand back contact of relay 5, conductors 42 and 55,right hand contact of relay 20 and through the winding of relay 45 to battery. Relay 45 is now energized and opensthe circuit previously traced through relays 44, 21 and 23. Relay 44 is accordingly deenergized and short circuits the input windings of the amplifiers A and A to, prevent ringing current from actuating the repeater. A holding circuit is established for relays 21 and 23, however, from ground over the front contact of relay 45 over conductor 46 and through the windings of relays 21 and 23 in parallel to battery. I

Returning to relay 20 a circuit is completed over the left hand front contact of said relay from ground over the lower front Relay 56 upon being energized establishes a locking circuit from battery through its winding and over its upper. front contact,

' over conductors 57 and 58, left hand normal contact of listening key K- -,'con :luctors 59 and 35 over the left hand back'contact of relay 1 and conductor 34 to'point 28 and thence to ground over the front contacts of relays 13 and 27. Relay 56 at its lower front contact completes a circuit from ground: over conductor 60, right hand back contact of relay 1. and through the lamp 61 tobattery. The lamp 61"is now caused to glow thereby indicating to the operator that a call has come in over one of the lines interconnected through the repeater. i 7

The operator upon observing the glowing of the lamp .61 will throw the listening key K to bridge her set across the cord. The actuation of the listening key opens the left; hand contact of said key thereby opening the locking circuits above traced for the relay 56. Relay 56 is accordingly dcen'ergized and the lamp (ilefl'aced. The right in addition to the rela hand contact of the listening key K is from the repeater and consequently the lines are associated through the cord connection, including conductors C, C the splitting key conductors C and C. T

i he operator having ascertained that the call came in over the line connected with the plug P may, if she desires, disconnecti the outgoing lineby throwing the splitting key K to the left so that she may com municate over the incoming line to the exclusion of the outgoing line. Should ringing current betransmitted from the out goingline with the circuit in this condition the ringing current would flow over conductors L right hand back contacts of relay; 1

and conductors L to the winding of the ringing" responsive relay 16. Relay 16lin respondingto the ringing current opens a circuit previously traced for the relay 19 (which circuit was restored as soon as the ringing current which actuated-relay 17 ceased) so that said relay 19 is again deenergized and causes the energization of relay 20. Relay 20 upon being energized does not complete a circuit over its right hand front contact for the relay 45 since the circuitof the relay 45] passes over the right hand contact of the listening key which con tact is now open. Relay 20, however, comletes the circuit of relay 56 at its left hand rout contact and alocking circuit for the the control of the splitting keyinstpadiof the listening key. Accordingly, the operator 1 upon observing the glowing of the lamp, realizes that a ringing call has been transmitted from the outgoing line since she is already in communication with the incoming line. By throwing the splitting key to the right, she may place herself in communication with the outgoing line to the ex clusion of the incoming line at the same time opening the locking circuit for relay- 56 which is accordingly cleenergized and e aces thelainp 61; i

-Upon restoring the listening key and splitting key to their normal condition the circuit previously traced for relays 4A, 21 and 23 will be againicomple'ted and the lines will be once more interconnected through the repeater;- Upon withdrawing the plugs and P from the jacks, the relays 8 and 9 will be deen'ergized thereby cf facing the lamp 7 and opening the circuits of-relays 13 and 27. The repeater control key K will also bercstored when the plugs are withdrawnfrom the jacks. The d'eenergization of relays 13 and 27removes the ground connection from point 28 so that relays 19, 29, 21, 23 and 44, the circuits of which it wil'l be remembered depended upon the ground connection to point 28, will be deenergized.

It will be noted that in the connection heretofore described as" having been set up i by the operator at position X, allo f the cir cuits whether transmission circuits through the repeater or controlling circuits leading to the keys K and K passed over the back contacts of the switching relays 1 to 5, inclusive. It will also be observed that for each of these circuits an alternative-path extended from the front contacts of these switching relays to the corresponding apparatus at position Y. The connections to position Y are therefore'all opened so that the operator at that position is unable to obtain control of the repeater by inserting the plugs P, and P inline jacks and the operator is further unable to interfere with the connection established at position X by manipulating the keys K 'fK i orK If, with the apparatus in its normal condition, the operator at position Y should'de-- sire to establish a connection between two the operator at position toll lines by inserting plugs P and P in the jacks of the desired lines, a circuit would be completed from the grounded sleeve contacts'of the incoming line jack, sleeve contacts of twin plug P through the winding of relay 10 and over the back right hand contacts of relays 9 and 8 to battery; A circuit would also be completed from the grounded sleeve contacts of the outgoing line over the sleeve contacts of the plug P through the winding of relay l1 andover the right hand'back contacts of relays 9 and 8 to battery. Relay 10 upon being energized at its left hand contact dis connects battery from the windings of'relays 8 and'9 so that the operator at position X is unable to cause the energization of these relays by attempting to setup a connection. At its right hand front contact relay 10 completes a circuit from ground throughthe resistance 12 and through the winding of relay 13 to battery. Relay 11 at its right hand front contact completes a circuit from ground through resistance 26 and through thewinding of relay 27 to battery. Relays 13 and 27 upon being energized connect ground at their lower contacts to the point 28 so that a circuit previously described is completed for the relay 19. Relay 11 at its left hand front contact completes a circuit from battery through the busy lamp 6 at position X to ground thereby causing the lamp to low to indicate to that the repeater is engaged. A circuit is also completed over the left hand front contact of relay 11 from battery through the windings of relays 1 to 5 inclusive in parallel and thence to ground so that the five switching relays are energized and shift the connections of the various transmission and controlling circuits leading from the repeater of Fig. 2 whereby said circuits are extended to the apparatus at position Y instead of position X. r

The circuit of the toll cord with the repeater disconnected may now be traced from the left hand tip and ring contacts of the twin plug P over conductors L left hand front contacts of relay 2, conductors L, back contacts of relay 21, conductors C, right hand front contact of relay '3, conductors G normal right hand and left hand contacts of the splitting key K over conductors 6,, left hand front contacts of relay 3, conductors C, back contacts of relay 23, conductors L, right hand front contacts of relay 4 and conductors L to the right hand tip and ring contactsof twin plug P The operator may include the repeater in the cord circuit by actuating the repeater control key K thereby completing a circuit from battery through the winding of filament control relay 29 over conductors 30 and 31, right hand make contacts of control key K over conductor 32, inner front contact of relay 5, conductors 33 and 14; to point 28 and thence to ground over the lower front contacts of relays 13 and 27. Relay 29 completes the filament circuit of the arm plifier-s A and A thereby rendering the tubes operative. A circuit is also'completed for relays 41, 21 and 23 from groun-dedpoint 28 over conductor 34, left hand front contact of relay 1, over conductors 35, and

36, lower normal right hand and left hand contacts of splitting key K right hand normalcontact of listening key K over conductor 37, inner right hand front contact of relay 1 over conductor 38, upper front contacts of relays 13 and 27, conductors 39 and 40', left hand make contact of key K conductor 41, left hand front contact of relay 5, conductors 42 and 43, winding of relay 14;, back contact of relay 45, conductor 416 and through the windings of relays 21 and 23 in parallel to battery. Relay 14 removes short circuits from the input windings of the repeater and connects the repeater to the input bridges 19 and 50 in a manner already described. The operation of relays 21 and 23 connects the repeater to the incoming and outgoing transmission circuits so that transmission between the two toll lines may take place through the repeater.

Transmission from the incoming line will pass over conductors L 1eft hand front contacts to-relay 2, conductors L, front contacts of relay 21 through the amplifier A, output circuit 53 and thence in parallel to the outgoing line and the balancing artificial line. The path to the outgoing line extends over the front contacts of relay 23, conductors L, right hand front contacts of relay 1 and over the conductors L The path to the artificial line extends over conductors N, left hand front contacts of relay 4 and over conductors N passes over conductors L front right hand contacts of relay 4, conductors L, front contacts ofrelay 23 through the amplifier A, output circuit 5 1- and thence in parallel to theincomingline and its corresponding balancing artificial line. The path to the incoming line extends over the front contacts of relay 21 and over conductors L, left hand In a similar manner, transmlssion from the outgoing line front contacts of relay 2 and conductors L,-. The path to the artificial line extends over conductors N, right hand front contacts of relay 2 and conductors N If ringing currents should be transmitted over the incoming line, the ringing responsive relay-17 would be actuated to open the circuit to relay 19 thereby causing the energization of relay 20. Relay 20 at its right hand front contact completes a circuit for the relay 45 from grounded point 28 over conductor 34, left hand front contact of re lay l," conductors 35 and 36, also contacts of splitting key K ri ht hand normal contact of listening key conductor 37 inner right hand front contact of relay 1, conductor 38, upper contacts of relays 13 and 27, conductors 39 and 40, left hand make contact of key K conductor 41', left hand front contactof relay 5, conductors42 and 55, front right hand contact of relay. 20 through the Winding of relay45 to battery.

Relay 45 opens the circuit of relay 44 and completes a holding circuit for relays 21 and 23 in a manner already described. The deenergization of relay 44 results in short circuiting the input windings of the repeater to prevent the transmission of ringingsurrent to the repeater.

elay 20 at its right hand front contact completes circuit for the relay 56 which is locked up over its upper front contact, conductor-s57 and 5 8, left hand normal contact of listeni key K,, conductors 57 and 35, left hand 1 ront contact of relay 1 over conductor '3.4 to grounded point 28. Relay 56 at its lower front contact completes a circuit from ground over conductor 60, right hand front contact of relay 1 and through the lamp 61' to battery. r

The (glowing of lamp 61 informs the operator that a ring has been transmitted over one of the lines and the o erato'r thereupon throws the listening key This operation results in deenergizing the relay 56 and effacing the lamp 61 since it will be remembered that the lockingcircuit of the relay 56 passed over the left hand contact of the listeningkey The circuit of relay 45 which passed over the right handcontact of the listening key is also opened so that said relay is deenergized and again connects relaysQl and 23 in circuit with the relay 44. The circuit for these relays, however, passes over the right hand contact of the listening key which is now open and consequently relays 21 and 23 as 'well as relay 44, are. de-

he repeater is now disconnectenergized. ed from the cord circuit and the operators set is bridged across the portion of the cord circuit including conductors C and C. By throwing the splitting key K, to the left, the operator may exclude the outgoing line from theconnection.

If, with the apparatus in this condition, a ring hould be transmitted from the outgoing line, relay 16 would be ractuated to again open the circuit of relay 19 and cause the energization of relay 20. Relay 45 is not now energized due to the energization of relay as its circuit is opened both at the right hand contact of the listening key and the lower left hand contact of the splittingkey, Relay 56 is energized, however,

and a locking circuit for said relay is providedover its upper front contact, conductors 57, 58 and 62, lowerleft hand make contact of splitting key K lower "right hand normal contactof said key,conductors that said relay is resorted and effaces the T e operator by restoring the splittingkey and listening key to normal again completes the circuit of relays 44, Qland 23 so that the line maybe again connected through the re peater.

storing the repeater control key K \Vithdrawing the plugs results in the dee'nergiza tion of relays l0 and'll so that the busy lamp 6 is elfaced and the switching relays l to 5 are restored to normal. .The'deenergization of relays l0 and .11 results in open-n p The connection may be taken down r by withdrawing the plugs P, and P, and re-- ing the circuits of relays 13 and 27which 0 upon heingrestored to normal disconnect. ground from point 28 so that rela'ys19,2l, 23, 29 and 44 are dee'nergized. The appag ratus is now restored to its original-condi at either position X or position Y.

-1n the connection heretofore described as tion and is ready to be used by the operators having been established at position. Y, it.

will be noted that all of the ci ron itsflewding. from the repeater, whether transmission o'ircuits or controlling circuits,were extended; over the front contacts of-theswitching re lays l-to 5, inclusive, to the apparatusat Position Y and were wholly disconnected from the apparatus at position X; Conse quently the operator at the latter position was unable to obtain control of the repeater or in any manner interfere with the c'onnec- 'tion established by the operator at position Y.

By meansof the arrangement above described, a simple and efiicient means isproe vided whereby the same repeater-may be used in establishing connections at different operators positions: thereby eliminating certain of the apparatus which would otherwise j be required with a consequent reduction in the expense involved.

.t will also be observed that the general principles herein disclosed may be embodied in many other organizations widely different 3 from that illustrated without departing from the spirit ofthe invention as defined in the following claims. Vhat is claimed is:

In a Signaling y a epeater, fly 0 plurality of lines, manual switching appaplurality of lines, manual switching appa ratus at one operators position for associating said repeater with any one or" said lines, a second manual switching apparatus at another operators position ior associating said repeater with one of a plurality of lines, and means "for placing said repeater under the controlof eitherswitching apparatus.

2. In a signaling system, ,a repeater, a

ratus at one operators position for ociating said repeater with any one 0;: .id lines, a second manual switching apparatus at 1- other operators position for associating said repeater with one oit' a plurality of lines, and means for placing saidrepeater exclusively under the control of either switching apparatus.

In a signaling system, a repeater, a

. plurality of lines, manual switching apparatus at one maerators position to] asso ing said repeater with any one oi? said lines,

second manual switch n apparatus at another operators position, ror associ said repeater with one 01" a plurality of: lines, and means whereby when said rep-eater is associatedwwith a line by one switching apparatus it is rendered independent of the other switching apparatus.

1. In a signaling system, a repeater, a plurality of lines, manual switching apparatus at one operators position for associating said repeater with any one of said lines, a second manual switching apparatus at another operators position for associating said repeater with one of a plurality of lines, and means whereby when said repeater is associated with a line by one switching apparatus it is disconnected from the other switching apparatus.

5. Ina signaling system, a repeater and circuits therefor, a plurality of lines, manual switching apparatus at one operators position for associating said repeater with any of said lines, a second manual switching apparatus at another operators position for associating said repeater with any one of a plurality of lines, repeater circuit controlling means associated with each switching apparatus, and means for placing said repeater under the control of either controlling means.

6. In a signaling system, a repeater and circuits therefor, a plurality of lines, manual switching apparatus at one operators position for associating said repeater with any of said lines, a second manual switching apparatus at another operators position for associating said repeater with any one of a plurality of lines, repeater circuitcontrolling means associated with each switching apparatus and means for placing said repeater exclusively under the control of either controlling means.

7. In a signaling system, a repeater and circuits therefor, a plurality of lines, manual pendentoi the controlling means associated with the other switching apparatus.

8. In a signaling system, a repeater and circuits therefor, a plurality of lines, manual switching apparatus at one operators position ttor associating said repeater with any or" said lines,-a second manual switching apparatus. at another operators position for -associating said repeater with any one of a plurality of lines, repeater circu1t,con-

trolling means associated with each switcliingqapparatus" and means whereby. when said' repeater associated with a. line by one switching apparatus it is disconnected from the controlling means associated with the other switching apparatus. y

9. In a signaling system, an amplifying repeater and associated circuits, a plurality of switchboard positions, through which onnections with said repeater may be established, and means for associating said repeater with any one of said switchboard positions. I i

'10. In a signaling system, an amplifying repeater and associated circuits, a plurality of switchboard positions, through which connections with said repeater may be established, and means whereby when a connection is established to said repeater through one of said switchboard positions said repeater is rendered independent of other switchboard positions.

11. In a signaling system, an amplifying repeater apparatus, a plurality of switchboard positions at the same exchange, repeater connections extending from said repeater apparatus, and means to extend said connections exclusively to any one of said switchboard positions.

12. In a signaling system, an amplifying repeater apparatus, a plurality of switchboard positions, repeater connections extending from said repeater apparatus and means whereby an operator at one switchboard position can control the extension of said connections to said position to the exclusion of other positions.

switchboard positions, switching means thereat, a repeater adapted to be connected to any one of said switchboard positions, means whereby when the switching means-at one position is actuated the repeater will be associated withthat position exclusivelyand abusy signal will be given. y i

15. In a signaling system, a plurality-of switchboard positions, lines terminating at said positions, a repeater, switching means at each position whereby said repeater may 7 ing means at one position is actuated to asso ci-ate the repeater with a line at that position the repeaterwill be. rendered independent of the controlling key at another position. 16. In a signaling system, a' plurality of switchboard positions, lines terminating at said position, a repeater, switchingmeans at each position whereby said repeater may be associated with any of the lines at that position, Controlling keysa't each position for controlling the functioning of the rewarm peater, and means whereby when the switching means atone position is actuated to associatethe repeater with a line at that position the repeater will be rendered independent of the switching means and controlling key at another position. i

17. In a signaling system, a plurality of switchboard positions, lines terminating at said positions, a repeater, switching means at each position whereby said repeater may be associated with any of the lines at that position, controlling keys at each position for controlling the functioning of the repe'ater, busy-signals at eachposition, and means whereby when the switching means at one position is actuated to associate the repeater witha line at that position therepeater will be rendered, independent of the switching means and controlling key at another position and'a busy signal will be actu- 3136C v t In testimony whereof, I have signed my name to this specification this 15th day of lVIay, 1919. v

OLIVER B. JACOBS. 

